The present invention relates to a panel with a frame (which will be hereinafter referred to as a panel unit), and also relates to a method for manufacturing such a panel unit.
It is known that a frame to be mounted on a peripheral edge of a panel such as a window glass for a vehicle is linearly molded by extruding synthetic resin, rubber or the like. The linear molding for the frame is then mounted on the peripheral edge of the panel and bonded thereto with a portion of the frame bent at each corner portion of the panel.
In such a conventional panel unit to be manufactured by employing a linear molding, much time and labor are required in mounting the frame on the peripheral edge of the panel and bonding the frame thereto. Furthermore, there is a possibility of wrinkling and floating of the frame at each corner portion of the panel or in the vicinity thereof. This tends to impair appearance of the panel.
A technique of eliminating the awkward operation in mounting the frame on the peripheral edge of the panel is disclosed in Japanese Laid-open Patent Publication No. 63-15716, for example.
According to this prior art technique, a panel is set within a pair of injection molding dies, and the dies are closed. Then, molding material such as resin and rubber is injected into a cavity defined around the peripheral edge of the panel, thereby forming a frame on the peripheral edge of the panel.
However, in the case that the panel is large in size, the cost of manufacturing the injection molding dies becomes high. This will increase the cost of manufacturing the panel unit.
Furthermore, in closing the injection molding dies, a closing pressure is applied to the panel which tends to damage the panel. Additionally, the molding surface of the dies is marred by the damaged panel, resulting in surface defects of the frame.
A technique for forming the frame on the peripheral edge of the panel is disclosed in the U.S. Pat. No. 5,057,265 by Kunert et al.
In this prior art technique, a frame is formed along the peripheral edge of a panel. However, such a technique does not permit formation of a frame which covers a part of the upper and lower surfaces and the end surface of the panel. Also, such a technique, if there is a variation in the external dimension of the panel, does not provide a panel unit having a predetermined external dimension.